The ear canal, or external auditory meatus, is a tube running from the outer ear to the middle ear. The ear canal extends from the pinna to the eardrum and is about 26mm in length and 7 mm in diameter.

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The outer foundation of the ear canal is cartilage covered with skin that contains hairs and glands that secrete wax. The hairs and wax (cerumen) help prevent foreign bodies, such as insects or dust, from entering the ear canal.

The ear canal protects the eardrum and acts as a resonator, providing about 10 dB of gain to the eardrum at around 3,300 Hz. The net effect of the head, pinna, and ear canal is that sounds in the 2,000 to 4,000 Hz region are amplified by between 10 and 15 dB. Sensitivity to sounds is greatest in this frequency region and therefore excessive noise in this range is the most likely to cause hearing damage.

The external auditory meatus is formed from the groove (cleft) of the first branchial arch.